[edk2-devel] [PATCH v2] OvmfPkg/PlatformInitLib: Fix integrity checking failed of NvVarStore in some cases
Lee, Chun-Yi
joeyli.kernel at gmail.com
Thu Dec 15 14:27:23 UTC 2022
In the commit 4f173db8b4 "OvmfPkg/PlatformInitLib: Add functions for
EmuVariableNvStore", it introduced a PlatformValidateNvVarStore() function
for checking the integrity of NvVarStore.
In some cases when the VariableHeader->StartId is VARIABLE_DATA, the
VariableHeader->State is not just one of the four primary states:
VAR_IN_DELETED_TRANSITION, VAR_DELETED, VAR_HEADER_VALID_ONLY, VAR_ADDED.
The state may combined two or three states, e.g.
0x3C = (VAR_IN_DELETED_TRANSITION & VAR_ADDED) & VAR_DELETED
or
0x3D = VAR_ADDED & VAR_DELETED
When the variable store has those variables, system booting/rebooting will
hangs in a ASSERT:
NvVarStore Variable header State was invalid.
ASSERT
/mnt/working/source_code-git/edk2/OvmfPkg/Library/PlatformInitLib/Platform.c(819):
((BOOLEAN)(0==1))
Adding more log to UpdateVariable() and PlatformValidateNvVarStore(), we
saw some variables which have 0x3C or 0x3D state in store.
e.g.
UpdateVariable(), VariableName=BootOrder
L1871, State=0000003F <-- VAR_ADDED
State &= VAR_DELETED=0000003D
FlushHobVariableToFlash(), VariableName=BootOrder
...
UpdateVariable(), VariableName=InitialAttemptOrder
L1977, State=0000003F
State &= VAR_IN_DELETED_TRANSITION=0000003E
L2376, State=0000003E
State &= VAR_DELETED=0000003C
FlushHobVariableToFlash(), VariableName=InitialAttemptOrder
...
UpdateVariable(), VariableName=ConIn
L1977, State=0000003F
State &= VAR_IN_DELETED_TRANSITION=0000003E
L2376, State=0000003E
State &= VAR_DELETED=0000003C
FlushHobVariableToFlash(), VariableName=ConIn
...
So, only allowing the four primary states is not enough. This patch changes
the falid states list (Follow Jiewen Yao's suggestion):
1. VAR_HEADER_VALID_ONLY (0x7F)
- Header added (*)
2. VAR_ADDED (0x3F)
- Header + data added
3. VAR_ADDED & VAR_IN_DELETED_TRANSITION (0x3E)
- marked as deleted, but still valid, before new data is added. (*)
4. VAR_ADDED & VAR_IN_DELETED_TRANSITION & VAR_DELETED (0x3C)
- deleted, after new data is added.
5. VAR_ADDED & VAR_DELETED (0x3D)
- deleted directly, without new data.
(*) means to support surprise shutdown.
And removed (VAR_IN_DELETED_TRANSITION) and (VAR_DELETED) because they are
invalid states.
v2:
Follow Jiewen Yao's suggestion to add the following valid states:
VAR_ADDED & VAR_DELETED (0x3D)
VAR_ADDED & VAR_IN_DELETED_TRANSITION (0x3E)
VAR_ADDED & VAR_IN_DELETED_TRANSITION & VAR_DELETED (0x3C)
and removed the following invalid states:
VAR_IN_DELETED_TRANSITION
VAR_DELETED
Signed-off-by: "Lee, Chun-Yi" <jlee at suse.com>
---
OvmfPkg/Library/PlatformInitLib/Platform.c | 9 +++++----
1 file changed, 5 insertions(+), 4 deletions(-)
diff --git a/OvmfPkg/Library/PlatformInitLib/Platform.c b/OvmfPkg/Library/PlatformInitLib/Platform.c
index 77f22de046..6963c47e0b 100644
--- a/OvmfPkg/Library/PlatformInitLib/Platform.c
+++ b/OvmfPkg/Library/PlatformInitLib/Platform.c
@@ -702,10 +702,11 @@ PlatformValidateNvVarStore (
VariableOffset = NvVarStoreHeader->Size - sizeof (VARIABLE_STORE_HEADER);
} else {
- if (!((VariableHeader->State == VAR_IN_DELETED_TRANSITION) ||
- (VariableHeader->State == VAR_DELETED) ||
- (VariableHeader->State == VAR_HEADER_VALID_ONLY) ||
- (VariableHeader->State == VAR_ADDED)))
+ if (!((VariableHeader->State == VAR_HEADER_VALID_ONLY) ||
+ (VariableHeader->State == VAR_ADDED) ||
+ (VariableHeader->State == (VAR_ADDED & VAR_DELETED)) ||
+ (VariableHeader->State == (VAR_ADDED & VAR_IN_DELETED_TRANSITION)) ||
+ (VariableHeader->State == (VAR_ADDED & VAR_IN_DELETED_TRANSITION & VAR_DELETED))))
{
DEBUG ((DEBUG_ERROR, "NvVarStore Variable header State was invalid.\n"));
return FALSE;
--
2.35.3
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